1. Field of the Invention
The present invention relates to a method of processing a substrate, which is adapted to perform a reflow process for forming a new resist pattern by dissolving a used resist pattern which has been formed in a photolithography step and used as a mask.
2. Background Art
For example, in the formation of an amorphous SiTFT (amorphous Silicon Thin Film Transistor) in a step of producing LCDs (Liquid Crystal Displays), multiple photolithography steps are required. Thus, in the past, multiple photolithography steps, i.e., exposing and developing steps, have been performed to form a photoresist pattern.
However, in the step of forming a TFT, a coating and developing apparatus and an exposing apparatus are required for each pattern desired to be obtained by etching, leading to a higher machinery cost.
In view of such an issue, a reflow process has attracted significant attention, in which a new resist pattern can be formed on a predetermined area (target) desired to be masked, by dissolving and changing the form of a resist pattern which has been once used as a mask. With this reflow process, a further process using a coating and developing apparatus and an exposing apparatus is no longer required for forming the second new resist pattern, thus reducing the machinery cost and enhancing the production efficiency.
Patent Document 1: TOKUKAI No. 2005-108904, KOHO
As described above, according to the reflow process, an exposing process using an exposing apparatus is not required upon remaking a resist pattern on a substrate, thereby reducing the production cost and enhancing the production efficiency.
However, in order to form a film having a uniform thickness with a sufficient amount of a resist on a target in the formation of such a new second resist pattern, the resist should be dissolved at an appropriately low speed. Therefore, such a process takes much time, thus degrading the efficiency